LOL, you also could use your own brain and look at the contact area and figure out it isn't working in any scale of efficiency like a properly sized surface would.
See the hot spot and see the thermal trail off? You're getting highly inefficient thermal transfer if you don't have anything contacting the surface immediately above the heat source (dies). This is why the center of mass and the internal fins are directly in the center of all of the AIO water cooling contact plates. They are designed for one die dead center not 2 dies spaced out and at a diagonal. This is inefficiency on inefficiency. Also, think about covering half of the above heat source with a heatsink... Now tell me, where does the heat flow across to get up into the heatsink? Back across a max'd our thermal region .. multiplying the heat that's in it.
Sure it works and that is likely not under persistent heat stress. God knows what this manifests in the long run.. At the temperature processors run at when max'd out, I'm sure you're going to get warping and all sorts of issues down the road. A freshman in college out of physics could tell you this. I can't believe actual people who do this for a living are lying to people and saying otherwise.... I'm not sure what type of fools they think people are.
yeah it can cause the soldier to break from uneven thermal expansion, i think in the mean time you can always solder the AIO contact plate to make larger surface area, maybe it will make the cooling performance worse but at least it will spread the heat evenly, and prevent uneven thermal expansion.